CO emissions from iron ore sintering have not been effectively controlled. Aiming at the oxidation problem of low-content CO in the sintering material layer, a quartz tube reactor is used to simulate the gas phase conditions in the sintering material layer, and the CO oxidation behavior in dry and wet bases is investigated under programmed temperature and constant temperature conditions. The results show that the introduction of steam significantly promotes CO oxidation and triggers the deflagration effect; under the condition of 8.0% water vapor, the CO oxidation reaction rate and degree are significantly improved, and the starting temperature is significantly reduced from 826 ℃ on a dry basis to 676 ℃, and CO oxidation is almost complete above 700 ℃; the steam injection or gas circulation technology on the material surface creates high temperature, water heating and oxygen bearing conditions for CO deflagration; the recommended water vapor volume fraction of the material surface air flow medium is 6.1% ~ 8.0% to avoid over-humidification of the material layer or insufficient conditions for CO deflagration. The research conclusions provide a theoretical basis for CO emission reduction during the sintering process and have guiding significance for production practice.